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Joe
 
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Default DR practice

If you want to sail a course of 080, at a speed of 10 knots and you
sail thru a current having an estimated set of 140 and a drift of two
knots

for 1 asa pt.
What would be your course and speed made good?.

If you want to sail a course of 095 through a current having a set of
170 and a drift of 2.5 knots, using a speed of 12 knots

for 1 asa point
What course would you steer and what would be your speed made good?

You want to sail a course of 265 and a speed of 15 knots through a
current having a set of 185 and a drift of 3 knots

For 1 more asa point
What course would you steer and what is your speed made good?


Joe
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Wally
 
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Default DR practice

Joe wrote:

I suspect that the speed you're looking for is the speed that would be
sailed through the water to acheive the desired course - speed made good is
the speed over the ground, isn't it (ie resultant of course/speed sailed and
drift/set)? I'll assume you're looking for course/speed through the water to
acheive the desired course and speed in the given conditions...


If you want to sail a course of 080, at a speed of 10 knots and you
sail thru a current having an estimated set of 140 and a drift of two
knots


069 at 9.17 knots.


If you want to sail a course of 095 through a current having a set of
170 and a drift of 2.5 knots, using a speed of 12 knots


083 at 11.61 knots.


You want to sail a course of 265 and a speed of 15 knots through a
current having a set of 185 and a drift of 3 knots


277 at 14.78 knots.


--
Wally
www.artbywally.com
www.wally.myby.co.uk


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Joe
 
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Default DR practice

"Wally" wrote in message ...
Joe wrote:

I suspect that the speed you're looking for is the speed that would be
sailed through the water to acheive the desired course - speed made good is
the speed over the ground, isn't it


Yes, Im talking about doing a DR plot SMG & CMG are the actual course
and speed you do.



(ie resultant of course/speed sailed and
drift/set)? I'll assume you're looking for course/speed through the water to
acheive the desired course and speed in the given conditions...


If you want to sail a course of 080, at a speed of 10 knots and you
sail thru a current having an estimated set of 140 and a drift of two
knots


069 at 9.17 knots.


Sorry Wally you are incorrect.

If you want to sail a course of 095 through a current having a set of
170 and a drift of 2.5 knots, using a speed of 12 knots


083 at 11.61 knots.


Very close to the course to steer, and your speed is off by almost a
knot


You want to sail a course of 265 and a speed of 15 knots through a
current having a set of 185 and a drift of 3 knots


277 at 14.78 knots.


277 is way off, but your real close on the speed, but not right on.

Sorry you flunked

Next! Come on Jax... show us what a skilled offshore navigator you
are!
Our you just a big mouth blowhard!

It's just a simple DR plot... Mr offshore bigshot!


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otnmbrd
 
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Default DR practice



JAXAshby wrote:
joe, you don't understand the definition of the term "DR".


jax, you don't know the definition of "DR", you only know A definition
of "DR", and the fact that *you* don't understand this is not surprising.

otn

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JAXAshby
 
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Default DR practice

over the knee, if you expand the definition to include gps charterplotters,
anything is possible.

same same if you expand the definition of breakfast eggs to include three
bricks of 24-k gold, you would be rich.

DR is speed vs time vs direction pointed, and your best guess as to where that
puts you. that's it, nothing more.

Some people believe that guessing as to current direction and strength and
guessing as to boat drift due to wind speed and direction improves their best
guess as to where they are, but it doesn't.

joe, you don't understand the definition of the term "DR".


jax, you don't know the definition of "DR", you only know A definition
of "DR", and the fact that *you* don't understand this is not surprising.

otn









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Wally
 
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Default DR practice

Joe wrote:
If you want to sail a course of 080, at a speed of 10 knots and you
sail thru a current having an estimated set of 140 and a drift of two
knots
What would be your course and speed made good?.


What do you mean by I "*want* to sail a course of 080, at a speed of 10
knots"? In this question, you ask for course and speed made good - so I have
to assume that, by "want", you mean 'the course I'm steering and my speed
through the water'. If that's the case, then the answer is 089 at 11.14
knots.


If you want to sail a course of 095 through a current having a set of
170 and a drift of 2.5 knots, using a speed of 12 knots
What course would you steer and what would be your speed made good?


Again, you use the term "want", but you ask for something different in the
answer - the course to steer and the speed made good. Clearly, the "course
and speed I *want*" doesn't have a consistent meaning. I may be a sweet,
innocent, fresh-faced n00b, but I'm not even sure that this question makes
sense. You give a course of 095 and a speed of 12 knots, but ask for course
to steer and speed made good. Therefore, 095 must be the course made good,
but 12 knots must be the speed through the water. I'll come back to this
shortly and see if I can work out an answer without having to do a degree in
maths.


You want to sail a course of 265 and a speed of 15 knots through a
current having a set of 185 and a drift of 3 knots

For 1 more asa point
What course would you steer and what is your speed made good?


As above - you ask for course to steer and speed made good. (Whips out copy
of Coastal Navigation and fires up AutoCAD...)


--
Wally
www.artbywally.com
www.wally.myby.co.uk


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Joe
 
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Default DR practice

"Wally" wrote in message ...
Joe wrote:
If you want to sail a course of 080, at a speed of 10 knots and you
sail thru a current having an estimated set of 140 and a drift of two
knots
What would be your course and speed made good?.


What do you mean by I "*want* to sail a course of 080, at a speed of 10
knots"? In this question, you ask for course and speed made good - so I have
to assume that, by "want", you mean 'the course I'm steering and my speed
through the water'. If that's the case, then the answer is 089 at 11.14
knots.

Ah I see what your saying, sorry.

Let me rephrase the question

Your sailing a course of 080 at a speed of 10 knots and you
sail thru a current having an estimated set of 140 and a drift of two
knots


What would be your course and speed made good?.






If you want to sail a course of 095 through a current having a set of
170 and a drift of 2.5 knots, using a speed of 12 knots
What course would you steer and what would be your speed made good?


Again, you use the term "want", but you ask for something different in the
answer - the course to steer and the speed made good. Clearly, the "course
and speed I *want*" doesn't have a consistent meaning. I may be a sweet,
innocent, fresh-faced n00b, but I'm not even sure that this question makes
sense. You give a course of 095 and a speed of 12 knots, but ask for course
to steer and speed made good. Therefore, 095 must be the course made good,
but 12 knots must be the speed through the water. I'll come back to this
shortly and see if I can work out an answer without having to do a degree in
maths.


You want to sail a course of 265 and a speed of 15 knots through a
current having a set of 185 and a drift of 3 knots

For 1 more asa point
What course would you steer and what is your speed made good?


As above - you ask for course to steer and speed made good. (Whips out copy
of Coastal Navigation and fires up AutoCAD...)



 
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